General Tracking Information

Overall, 97.06% of samples had a recorded gaze position.

The total number of blocks in this design was 105. This was calculated as the number of trials multiplied by the number of blocks within each trial.

Out of those blocks, 0 were completely missing data. These missing blocks can be seen below:

trials_this_n block n tracked perc

The percent of samples tracked within each block can be seen below:

trials_this_n block n tracked perc
0 fixation 979 979 100.00
0 stimulus 3499 3280 93.74
0 text 3011 2939 97.61
1 fixation 991 898 90.62
1 stimulus 3499 3358 95.97
1 text 3008 2937 97.64
2 fixation 976 736 75.41
2 stimulus 3499 3430 98.03
2 text 3009 2944 97.84
3 fixation 974 974 100.00
3 stimulus 3499 3381 96.63
3 text 3010 2950 98.01
4 fixation 992 992 100.00
4 stimulus 3499 3202 91.51
4 text 3005 2924 97.30
5 fixation 979 979 100.00
5 stimulus 3499 3416 97.63
5 text 3009 2825 93.89
6 fixation 974 974 100.00
6 stimulus 3501 3278 93.63
6 text 3010 2928 97.28
7 fixation 989 975 98.58
7 stimulus 3501 3415 97.54
7 text 3009 2847 94.62
8 fixation 991 912 92.03
8 stimulus 3499 3364 96.14
8 text 3004 2925 97.37
9 fixation 980 980 100.00
9 stimulus 3500 3442 98.34
9 text 3008 3007 99.97
10 fixation 993 993 100.00
10 stimulus 3482 3402 97.70
10 text 3003 3003 100.00
11 fixation 981 946 96.43
11 stimulus 3499 3446 98.49
11 text 3007 2904 96.57
12 fixation 977 878 89.87
12 stimulus 3499 3425 97.89
12 text 3010 2918 96.94
13 fixation 991 991 100.00
13 stimulus 3499 3423 97.83
13 text 3011 3011 100.00
14 fixation 988 870 88.06
14 stimulus 3501 3501 100.00
14 text 3010 2942 97.74
15 fixation 990 990 100.00
15 stimulus 3499 3402 97.23
15 text 3011 2924 97.11
16 fixation 992 890 89.72
16 stimulus 3498 3486 99.66
16 text 3006 2921 97.17
17 fixation 978 891 91.10
17 stimulus 3499 3409 97.43
17 text 3004 2920 97.20
18 fixation 979 979 100.00
18 stimulus 3501 3434 98.09
18 text 3010 2933 97.44
19 fixation 990 990 100.00
19 stimulus 3499 3382 96.66
19 text 3010 2954 98.14
20 fixation 992 992 100.00
20 stimulus 3498 3334 95.31
20 text 3004 2914 97.00
21 fixation 980 980 100.00
21 stimulus 3500 3427 97.91
21 text 3010 2922 97.08
22 fixation 990 891 90.00
22 stimulus 3499 3421 97.77
22 text 3010 2928 97.28
23 fixation 991 991 100.00
23 stimulus 3500 3421 97.74
23 text 3008 2945 97.91
24 fixation 975 975 100.00
24 stimulus 3500 3329 95.11
24 text 3010 2937 97.57
25 fixation 991 991 100.00
25 stimulus 3497 3328 95.17
25 text 3006 2932 97.54
26 fixation 979 979 100.00
26 stimulus 3499 3202 91.51
26 text 3010 2938 97.61
27 fixation 991 991 100.00
27 stimulus 3499 3433 98.11
27 text 3010 2918 96.94
28 fixation 991 991 100.00
28 stimulus 3499 3439 98.29
28 text 3003 3003 100.00
29 fixation 981 824 84.00
29 stimulus 3500 3390 96.86
29 text 3010 2934 97.48
30 fixation 989 989 100.00
30 stimulus 3501 3439 98.23
30 text 3005 2918 97.10
31 fixation 978 978 100.00
31 stimulus 3500 3450 98.57
31 text 3003 2795 93.07
32 fixation 981 955 97.35
32 stimulus 3499 3373 96.40
32 text 3010 2861 95.05
33 fixation 991 991 100.00
33 stimulus 3500 3436 98.17
33 text 3002 3002 100.00
34 fixation 981 898 91.54
34 stimulus 3500 3500 100.00
34 text 3013 2852 94.66

Gaze Position

All gaze position data is taken after the instructions were completed. Presented data is average gaze position as given by the eyetracker. Samples where no eyetracking data is recorded are removed from the overall count.

  • % of time participant was gazing on screen: 99.68%.
  • % of time participant was gazing within the stimulus area during stimulus blocks: 99.01%.

Pupil Size

Distribution of Pupil Sizes

Eyelink reports pupil data from left and right eyes as well as the average of the two. The preprocessing pipeline performs mean and median normalization on all 3 measures relative to prefixation and fixation baselines. The following plots show the distribution of pupil sizes for samples where the participant has their gaze on the screen during the experiment (i.e. past the instructions block).

Pupil Sizes During Stimuli

Epoch Median

Median average (combined left and right values) pupil size is plotted for each stimulus block as a function of epoch. Raw values are plotted followed by prefixation and fixation-normalized values, respectively. Within stimulus blocks, patterns of change in pupil size are not different across the raw and two types of normalization, however the differences pupil size between blocks does differ across normalizations. The extent to which they differ is dependent on the variance in pupil size during the chosen normalization block across samples.

Pupil Size and Gaze Position

Median average pupil size are plotted as functions of gaze position during stimulus blocks. Only positions within the boundary of the stimulus area are plotted. Non-normalized median values are plotted first followed by prefixation normalized, and then fixation normalized.

Raw Pupil Size

Prefixation Normalized

Fixation Normalized